Apparatus for making prestressed structural members



c. w. JONES 3,049,786

APPARATUS FOR MAKING PRESTRESSED STRUCTURAL MEMBERS Aug. 21, 1962 3Sheets-Sheet 1 Filed May 28, 1958 IIIIIIIIL INVENTOR CORDIS W. JONESTORNEY Aug. 21, 1962 c. w. JONES 3,049,736

APPARATUS FOR MAKING PRESTRESSED STRUCTURAL MEMBERS Filed May 28, 1958 3Sheets-Sheet 2 GROUND LEVEL FIG. 3

INVENTOR. CORDIS W. JONES ZMMMM ATTORNEY Aug. 21, 1962 c. w. JONES3,049,736

APPARATUS FOR MAKING PRESTRESSED STRUCTURAL MEMBERS Filed May 28, 1958 5Sheets-Sheet 3 INVENTOR. CORDIS W. JONES ATTORN EY 3,049,786 APPARATUSFOR MAKING PRESTRESSED STRUCTURAL MEMBERS Cordis W. Jones, Wichita,Kans. (5142 W. Nevada Place, Denver 19, Colo.) Filed May 28, 1958, Ser.No. 738,564 4 Claims. (Cl. 118) This invention relates to concrete. In amore specific aspect, this invention relates to concrete members orarticles of manufacture. In a still more specific aspect, this inventionrelates to such members or articles of manufacture and method and meansfor producing them.

In yet a more specific aspect, this invention relates to means formaking so-called pre-stressed concrete members or articles ofmanufacture having therein tensioned reinforcing members of wire and/ orcable. Another specific aspect of this invention relates to a new methodto produce such pre-stressed concrete members. In still a more specificaspect, this invention relates to means for making structural members ofconcrete known as pre-stressed concrete beams, etc., having thereinreinforcing members preferably of Wire and/or cable which are undertension and which are pre-tensioned before manufacture of such concretestructural members, and this invention specifically relates to a methodof making such pre-stressed concrete members, such method and meanspreferably specifically pertaining to means and methods of making suchas pre-stressed concrete I-beams, channel beams, double T beams, poles,piling, beams of square cross section, beams of fluted-shape in crosssection, and the like.

Concrete has long been known, and it is used for the construction ofmany different things, for example, highways, footings and foundationsfor buildings, building walls and ceilings, roofs, and the like, wherethe concrete is in monolithic form, and normally in these usesreinforcing members of metal rod are built into the slabs or sections ofmonolithic concrete to strengthen same. These reinforcing metal rods aremerely positioned to extend through the forms for making the concretesection and are not placed under tension before contacting with theconcrete.

Fairly recently relative to time, it has been known and is common in theprior art to make and use so-called prestressed concrete members, andthese can be and are used for all kinds of structural purposes,generally being usable where wood or metal beams, poles, pilings, etc.,can be employed in the building and construction industries. Thesepre-stressed concrete structural members of beam, pole, piling, and thelike, shape are built and formed with substantially longitudinalreinforcing metal wire and/or cables therein embedded in the concrete.These reinforcing wires and/or cables pass through the mold meansemployed to form the concrete member of desired shape prior tointroduction and contact therewith with the concrete to form the member,and the reinforcing wires and/ or cables are placed under tension, withsuch tension being maintained on the wires and/or cables during thesetting and for a portion of the curing time of the member being formed.The result is a concrete beam member which is pre-stressed prior to usein construction, and these beams are much stronger than the beam whichhas no pre-stressing. The advantage of this to the construction orbuilding industry is apparent. Smaller members can be employed to carrythe same load as a much larger beam which is not pre-stressed. Lessmaterial can be used in construction of the beam members, and materialsof relatively low cost. Economic concrete can be used in many places toreplace relatively expensive steel and wood. Concrete can be used toconstruct the frame work of buildings, without the necessity 3,049,786Patented Aug. 21, 1962 of forming up and pouring on the job. And, theconcrete structural members will outlast almost any other kind ofsuitable replacement material, not being subject to corrosion from theelements, and not being attacked by such as termites.

In the prior art it has been a practice to make these so-calledpro-stressed concrete beams or poles by simply building a stationaryform of wood or metal, stretching reinforcing wires and/ or cablesthrough the mold in proper position, tensioning the reinforcing wiresand/ or cables to the desired tension, pouring concrete into the mold tofill it, letting the concrete set up in the mold, removing the mold fromaround the formed concrete beam or vise versa, allowing the formedconcrete beam to cure to the desired point, and cutting of thereinforcing wires and/ or cables at the ends of the beam. This methodand means of producing the pre-stressed concrete beams is very tedious,expensive, and time consuming. Setting and curing times of up to 96hours are commonly employed, and this ties up a lot of form equipment.Also, it is very diflicult in operation to handle the forms, forexample, to space them properly to make it easy and rapid to introduceconcrete thereinto.

Other method and means have been proposed, one of which is to moveindividual forms in series along a base, bringing them to a halt to fillthe forms and then moving the forms to an agitation and curing area, andin this means the reinforcing wires and/ or cables are common to all theforms in the series being fed from a plurality of spools of therein-forcing material. These means perhaps make it easier to introducethe concrete into the forms, since they are moved to the dispensingmeans, but the tieing up of the equipment and expensive time consumptionmakes the proposed method and means disadvantageous. Further, difiicultyis encountered in properly feeding out the reinforcing wires and/ orcables because of the necessity of maintaining considerable tensionthereon. All of the methods and means of the prior art are undesirablein several respects.

I have invented new apparatus for making concrete members. The apparatushas a base. A mold is used which has a passageway therethrough. Inoperation the concrete is introduced into the mold through means thereinor therewith providing for such. The mold is mountable to move relativeto the base, and means are preferably provided to move the mold inrelation to the base. The new apparatus of my invention is adapted tomake a concrete member by moving the mold relative to the base andintroducing concrete into the mold. Preferably, a mold member isemployed which moves along the base, with the base forming a portion ofthe mold, usually the bottom of the mold, and reinforcing members,preferably metal wires and/ or cables, pass through the passageway inthe mold under tension. The mold member in operation moves relative tothe reinforcing members. By the new method of my invention for makingconcrete members, concrete is passed into a mold movably mounted to moverelative to a base. A portion of the concrete is solidified in the moldduring operation. And, during operation the mold is moved relative tothe base to a position out of contact with a portion of the resultingconcrete solidified in the mold to thereby produce a portion of a formedconcrete member. Preferably, reinforcing members are provided and passthrough the mold and are maintained therein during the introduction andcontact with the concrete. These, of course, are preferably metal wireand/or cable reinforcing members.

The new method and means of my invention for making concrete members isvery advantageous. It can be used in a continuous operation to make aplurality of such concrete members using one mold means. Equipment andapparatus is not tied up in time consuming and expensive delay. Theapparatus can be made very functional to be easily transportable. Inmaking pre-stressed concrete beams, poles, piling, and the like, thereinforcing metal wires and/ or cables are pre-tensioned and mounted,and remain stationary during'the forming, setting, and curing stages ofthe process. Thus, the apparatus is very reliable in use. The mold meansemployed in the apparatus is very accessible in operation so that theconcrete can easily and conveniently be introduced into the mold. Movingequip ment hauling ready-mixed concrete which is available in almostevery city of any size can be brought up in close relation to the moldduring operation to pass or dump the ready-mixed concrete into the moldof the apparatus. This can be done continuously or semi-continuously informing a pro-stressed concrete beam or a plurality of beams. The newapparatus of my invention can be made any length desirable, and it canbe made to produce in one continuous operation a great number ofconcrete members, using a plurality of individual mold means or memberswhich operate in parallel, each of the units in parallel producing aseries of concrete members, if desired. The new apparatus of myinvention is easy and inexpensive to manufacture, and reliable andeconomic in use and to repair.

Itis an object of this invention to provide new concrete handling methodand means.

It is another object of this invention to provide new method and meansfor making concrete members or articles of manufacture.

Still another object of this invention is to provide new method andmeans for making so-called pro-stressed concrete members or articles ofmanufacture having reinforcing members in tension therein, preferablywire and/ or cable reinforcing members.

Yet another object of this invention is to provide new method and meansfor making such pre-stressed concrete structural beams continuously orsemi-continuously, and such *beams having reinforcing members preferablyof metal and/ or cable therein which are pre-tensioned beforemanufacture of such concrete structural beams.

It is still another object of this invention to provide new method andmeans for making pre-stressed concrete structural beams, poles, piling,and the like, which is easy and inexpensive to make and use, andreliable and economic in use.

Other objects and advantages of the new method and means for makingconcrete members of my invention, particularly pre-stressed concretestructural members having pre-tens'ioned metal wire and/ or cablereinforcing members therein, will become apparent to those skilled inthe art upon reading this disclosure.

Drawings accompany and are a part of this disclosure. These drawingsdepict preferred specific embodiments of the new apparatus of myinvention for making pre-stressed concrete structural members, and it isto be understood that the drawings are not to unduly limit. the scope ofmy invention.

In the drawings,

FIG. 1 is a perspective view of a preferred specific em.- bodiment ofthe apparatus of my invention designed to make continuously orsemi-continuously a pre-stressed concrete structural beam ofsubstantially I-beam shape, or a plurality of such pre-str-essedconcrete beams.

FIG. 2 is an enlarged partial cross-sectional view taken on line 22 ofFIG. 1.

FIG. 3 is a view taken on line 3-3 of FIG. 2.

FIG. 4 is a view taken on line 44 of FIG. 2.

FIG. 5 is a side elevation view, cut away in the central portion, of apre-stressed concrete structural I-beam made with the apparatus of FIGS.1 through 4 of my invention, and by the new method of my invention.

FIG. 6 is a perspective view of a preferred specific embodiment ofreinforcing member deflecting means of my invention which is preferablyremovably mountable in 4 cooperative combination with the apparatus ofmy invention shown in FIGS. 1, 2, and 4.

FIG. 7 is an enlarged transverse cross-sectional view through the moldmember of the apparatus of my invention shown in FIGS. 1 through 4, andshowing in crosssection a formed and reinforced pre-stressed concretestructural I-beam.

FIG. 8 is a side elevation view of a preferred specific embodiment ofbulkhead means of my invention preferably used with the apparatus of myinvention to provide for producing pie-stressed concrete structuralbeams wherein the reinforcing members are not parallel to thelongitudinal axes of the beam produced, but only sub stantiallylongitudinal thereof.

FIG. 9 is a perspective view partially cut away of a pre ferred specificembodiment of apparatus of my invention wherein the mold means depictedis such as to produce concrete members in parallel operation, and on abase and other means similar to that depicted in FIGS. 1 through 4.

Following is a discussion and description of my invention made withreference to the drawings whereon the same reference numerals are usedto indicate the same parts and/or structure. The discussion anddescription are made in connection with preferred specific embodimentsof the new apparatus and methods of my invention for making concretemembers, and it is to be understood that the discussion and descriptionare not to unduly limit the scope of my invention.

Referring now to the drawings, FIGS. 1 through 7, a preferred specificembodiment of the apparatus of my invention is shown for making anI-beam of pre-st-ressed concrete, such beam having pre-tensioned metalwire and/or cable reinforcing members approximately longitudinal thelongitudinal axis of the I-beam and embedded therein. The apparatus hasa base 11 which is preferably elongated to make one or more beams, andthe base is relatively smooth and flat in its operating portion which iscentral of the sides of the base. End members 13 are at opposite ends ofbase 11, and they are positioned in mirror image relation as shown inFIG. 1 of the drawings. The base 11 and end members 13 can be made ofany suitable material, such as concrete, metal, and/or wood, and thebase 11 can be made integral with end members 13, as indicated in thedrawings, or the end members 13 can be separate from the base andanchored or set into the ground. Also, if desired, base 11 can be madein sections to make the apparatus more portable. I have found itconvenient for a stationary location to make base 11 of monolithicconcrete reinforced with metal rod, with the base extending down intoand set into the ground (FIG. 2). The outer foundation sections 15, andan inner foundation section 17 have been found suitable and desirablefor such an installation. The end members 13 can suitably be poured andformed at the ends of base 11 with the lower portions of end members 13extending down into the ground, if desired.

The base 11 has guide means rigidly secured thereon and formed by spacedand parallel members 19 which are preferably metal angle irons suitably'bolted to the base, such as 'by setting bolts into the concrete of base11. Of course, other suitably shaped members can be used to providethese guide means, and if the base is made in sections the guide meanscan be mounted on each section to coincide to provide a continuous guidewhen the sections are placed and positioned end to end for use.

In operation and prior to the use of the new apparatus of my inventionto produce pre-stressed concrete beams, a plurality of metal wire and/orcable reinforcing members, preferably of steel, are stretched betweenthe end members 13 longitudinal of base 11 and in spaced relationthereto. These reinforcing metal wire and/or cable members 21 can beused in any number and position desired. They are pre-tensioned andmaintained under tension during the forming of the concrete beam member,the solidifying step, and during at least a portion of the curingoperation to finally produce the pre-stressed concrete beams. Endmembers 13 are provided with attachment means 23 for mounting andholding wires and/or cables 21 in tensioned condition during the beamforming operation. Any suitable means can be used to stretch reinforcingmembers 21 and put them under desired tension. The wires and/or cablescommon to the prior art for producing pre-tensioned and pre-stressedconcrete beams can be used with the apparatus of my invention to producesuch pre-stressed concrete beams by the new method of my invention.

A plurality of wire and/ or cable reinforcing member deflectingassemblies 25 are removably mounted on base 11 in spaced relation, andin operation wires and/or cables 21 contact these assemblies 25, withthe wires and/ or cables deflected out of true parallel alignment withbase 11. Also, deflecting assemblies 25 can be employed to pre-tensionwires and/or cables 21 by deflecting them from out of true orsubstantially true straight alignment when they are stretched betweenend members 13 and secured thereto by mounting means 23. The manner ofdoing this will be set forth hereinafter. Deflecting assemblies 25preferably have a plurality of substantially vertically positionablemembers, namely middle member 27 and side members 29. Preferably thesemembers 27 and 29 are constructed of steel rod or pipe. A plurality ofspaced and horizontally positionable members are preferably rigidlymounted on members 27 and 29 in any suitable manner to produce aChristmas tree-type of arrangement, namely lower horizontal channelmember 31 mounted on members 27 and 29 and middle and upper channelmembers 33 mounted on member 27. It has been found suitable to weldmembers 31 and 33 to vertical support members 27 and 29, and inproducing a prestressed concrete beam by the new method and means of myinvention, these members remain in the beam embedded therein uponproducing same. This is accomplished after forming the beam by cuttingoff the lower end portions of members 27 and 29 along the bottom of thebeam as formed.

The deflecting assemblies 25 are preferably made removably mountable onbase 11. Heavy anchoring bars 35, preferably of steel, are mounted intransverse recesses 37 formed in the top of base 11. Two bars 35 aremounted in spaced relation in each recess 37 as shown in the drawings.Bars 35 are suitably anchored in rigid position, preferably by nut andbolt means, the bolts 39 of which are embedded in central portion 17 ofbase 11 with the upper or outer end portions of bolts 39 passing betweenbars 35. The outer ends of bolts 39 are threaded to receive nuts 41, andit is preferred to use clamping washers 43 on both sides of bars 3-5,such fitting over bolts 39. Spaced bars 35 also receive therebetween tomount, the head end portions of bolts 45 with the heads proper of bolts45 engaging the lower edge of spaced bars 35. A channel member 47 ismovably mounted in recess 37 in base 11 to move up and down in therecess as desired, to tension wires and/or cables 21. The sides ofchannel member 47, which is mounted in inverted position, fit over thesides of spaced bars 35 to receive same in slidable relation thereto.Bolts 45 pass up through holes 49 in the top of channel member '47 whenmounted, and nuts 51 on bolts 45 position and maintain channel member 47as desired relative to fixed bars 35. Bolts 45 are threaded on theirupper end portions, so that by turning nuts 51 channel member 47 can beforced downwardly or released to move upwardly, as desired. A plate 53is mounted on base 11 to cover recess 37 therein between the angle irons.19 which form the guide means for the mold member of the apparatus.This plate 53' preferably of steel then forms the upper surface of thebase 11 over recess 37 in the central portion of the base which, as willbe seen hereinafter, forms in operation a portion of the mold employedto form pre-stressed concrete beams. The vertically disposed deflectingmembers 27 and 29 pass down through holes in plate 53 and correspondingholes in the upper portion of inverted channel member 47. The lower endsof these members 27 and 29' are threaded to receive nuts 55 which whenengaged mount the deflecting assemblies to move with channel member 47.By this means upon tightening nuts 51, with nuts 55 engaged on members27 and 29 passing through the upper portion of channel member 47, thedeflecting assembly members 31 and 38 in contact with wires and/ orcables 21 thereunder can be moved downwardly against the force of thetension of members 21 to place wire and/ or cable reinforcing members 21under more tension. This has been found very satisfactory in operation.

A mold member at; having sides 6 2, a top 64, and a passageway 66therethrough, and open in the ends and bottom is slidably mounted onbase 11 to move therealong between guide means or angle irons 19. Moldmember 60 in combination with base 11. between guides 19 forms the moldof the apparatus of my invention. Mold member '60 can be made of anysuitable material, preferably iron or steel, and sides 62 thereof haveinwardly projecting portions 68 which provide for a cross sectionalshape of passageway 66 to form in operation a pro-stressed concrete beamof I-beam shape. Mold member 60 has open hopper means 70 in the top 64thereof through which concrete is passed or poured during operation tomake pre-stressed concrete beams. As one skilled in the art can see,this is very advantageous because a common or usual truck haulingready-mixed concrete can back up or come alongside the apparatus toeasily dump concrete through a delivery spout into lhopper 70 and thusinto the mold of the apparatus. Of course, any suitable means andmethods to introduce concrete through hopper 70 into the mold can beused, and if desired, a common overhead track arrangement can beprovided for moving a hopper of concrete along the apparatus in dumpingrelation to mold member 60 and the hopper 70 thereof. In this connectionI have found it convenient in some instances to provide commonsuperstructure framework to support mold member 60 'and/ or a movinghopper of concrete supply, or mold member 6%? can be made heavy enoughto operate properly without support.

In operation mold member 60 is slid along base 11, and cable 75 attachedto mounting member 77in turn attached to mold member 60 has been foundsatisfactory and desirable to accomplish moving of mold member 60relative to base 11. A winch 70 suitably mounted on right end member 13has been found convenient to receive and wind cable 75 to move moldmember 60. Any suitable powering means, such as motor 81, can beemployed to wind winch 79 in operation.

The apparatus of my invention as depicted in FIG. 1 can be used toproduce a single pre-stressed concrete beam or a plurality ofpre-stressed concrete beams in series, with the reinforcing wires and/orcables 21 deflected by assemblies 25 as shown and being approximatelylongitudinal to the beam formed, the exception being at the end portionsof base 11v where reinforcing members 21 project upwardly slightly as aresult of deflection. When a plurality of beams are made in series byapparatus having a base 11 long enough, a bulkhead member 84 (FIG. 8) ispreferably used and mounted on base 11 between angle iron guides 19' atone end or both ends of the space providing for the beams to be formed.These bulkhead means 84 have aperture means to receive wires and/orcables 21, such being indicated by dotted lines at 86 in FIG. 8. Thewires and/or cables 21 hold the bulkheads 84 down in operation. Afteroperation to form the concrete beams, the wires and/ or cables 21 arecut and the bulk heads removed from the apparatus. Apertures 86 can beplaced in bulkheads 84 as desired, so that, if desired, wires and/ orcables 21 will pass up and down in relation to base 11 and so that theywill have this position in the final beam formed by the apparatus in itsoperation, or apertures 86 can be placed and positioned 7 so that wiresand/ or cables 21 will stay in approximately a straight line spaced frombase 11 throughout substantially the length of base 11.

In FIG. 9 is shown another preferred specific embodiment of apparatus ofmy invention which is preferably used to produce a plurality ofpro-stressed concrete beams in parallel, and in operation each of theparallel lines can produce a plurality of such beams in series. A base11 and end members 13 like in the embodiment of FIG. 1 can be utilized,and the manner of operation and mounting of deflecting assemblies 25 canbe the same as in the apparatus of FIG. 1. Angle iron guides 19 mountedon base 11 are employed the same as in the apparatus of FIG. 1. Ofcourse, base 11 would be larger in width in this instance and guidemember 19 would be spaced apart more widely. Also, deflecting assemblies25 would be set and mounted in channel members 4-7 side by side, aswould be the case with the bulkhead means 84 mounted on base 11, if suchare employed, and they can be. Twin mold members 91, each being verysimilar to mold member 60 of the embodiment of FIG. 1 are mounted sideby side in slidable relation to base 11, and in operation move alongbase 11 between angle iron guides 19. These mold members 9 1 have acommon open hopper means 93 with divider means 95 to introduce concreteinto both molds during operation, such molds formed by mold members 91and the central portion of base 11 between guides 19. The mold members91 are shaped inside the same as mold members 60 of the embodiment ofFIG. 1, so that in operation they produce a I-beam shape of pro-stressedconcrete member. Like mold member 60, they can be shaped to produce anyshape of pre-stressed concrete beam desired. In this instance operatingcable 75 is attached by a forked member 99 to mold members 91 so thatthey can be moved together along the length of base 11.

In operation to produce pre-stressed concrete beams by the method of myinvention with either of the specific embodiments of my inventionpreferred and shown in the drawings, the mold members are positioned onbase 11 at the end away from winch 79, and so that the mold membersenclose the reinforcing wires and/or cables 21 stretched between endmembers 13. These reinforcing wires and/ or cables 21 then pass throughthe mold formed by the mold members and base 11, and underneath theChristmas tree-type deflecting assemblies, that is under the horizontalmembers or arms 31 and 33 thereof, which deflect the wires and/or cables21 to tension them desirably along with the tension placed upon them bystretching them between end members 13. Concrete is poured into the moldmembers (through hopper 70 or 93), and it flows into and fills the spacewithin the mold members and comes into contact with the reinforcingwires and/or cables 21. It is prefererd to agitate the concrete withinthe mold members and this can be suitably done by a portable agitatorstuck down into the concrete in the mold, the agitating member beingvibrated to see that the concrete properly fills the mold and toeliminate entrapped air, and the like. In starting the operation, aperiod for the concrete set up is allowed, and when the concrete has setup enough to maintain its form in the shape produced by the mold, themold member or members are moved by Winch 79 and cable 75. A portion ofthe resulting solidified concrete within the mold remains stationary andthe mold members 60 or 91 move out of contact therewith in the rearportion of the mold. Additional concrete is then introduced into themold formed by the mold members and base 11 through hopper 70 or 93,additional agitation is performed on the newly introduced concrete, andit is allowed to solidify in the manner of the first concreteintroduced. The mold members 60 or 91 are then moved further along base11 and out of contact with another portion of concrete which hassolidified in the mold. This new portion out of contact with the moldmembers then becomes an additional integral portion of a formedprestressed concrete member. Once the operation has been started, it canbe continued in a continuous or semi-continuous operation until the moldmember or 91 has traveled the complete operating length of base 11,length enough so that the remaining portion of the base can be used tomove the mold members out of contact with formed concrete members forremoval of the form members from base 11. The end of the beam memberformed or the last beam formed in series can be established by using abulkhead means 84 on base member 11 and held thereon by the tension ofwires and/or cables 21. The formed pre-stressed concrete members arethen cured the desirable amount, up to 96 hours in usual circumstances,and it has been found desirable to maintain tension on wires and/ orcables 21 during a substantial portion of this time. When the beams havecured sufiiciently for removal from the apparatus, the deflectingassemblies 25 are disassembled by removing nuts 51 from bolts 45, thisallowing the removal of channel members 47 from recesses 37. The channelmembers are removed from members 27 and 29 by removing nuts 55therefrom. This then releases plates 53 for removal from thepre-stressed concrete beams formed on the underneath side. It ispreferred to cut oil the ends of members 27 and 29 flush with the faceof the concrete beam formed and through which they project, and wiresand/ or cables 21 are preferably cut off flush with the ends of thebeams. The em bedded portions of deflecting assemblies 25 then remain inthe pre-stressed beams along with wires and/or cables 21 to reinforcethe beams. The pre-stressed concrete beams made by these preferredspecific embodiments of the apparatus of my invention by the new methodof my invention is shown in side elevation in FIG. 5, and identified bynumeral 100. The cross section shape of this beam 100 of I-beam shape isshown in FIG. 7, as is the spacing and positioning of reinforcing wiresand/or cables 21 therein. Of course, these wires and/or cables can bespaced and positioned as desired.

As will be evident to those skilled in the art, various modifications ofmy invention can be made, or followed, in the light of this disclosureand discussion, without departing from the spirit or scope of disclosureor from the scope of the claims. Specifically, beams, poles, pilings,and the like, of any desired shape and size can be made by the newmethod and means of my invention.

I claim:

1. Apparatus for making pre-stressed concrete structural beam membershaving prc-tensioned metal elongated reinforcing members substantiallylongitudinal therein and under great tension, comprising, incombination, an elongated and relatively smooth and flat base, aplurality of transversely extendng recesses in said base, end membersrigidly secured to said base in mirror image relation with one of saidend members at each of the end portions of said base, spaced andsubstantially parallel guide means secured to said base and extendinglongitudinally substantially the length thereof, each of said endmembers having means constructed to anchor end portions of a pluralityof said reinforcing members stretched therebetween under great tensionand in vertical and horizontal spaced relation, anchoring means, each ofsaid recesses in said base having one of said anchoring means therein,each of said anchoring means including upwardly projecting bolt means, aplurality of permanently embedable deflecting assemblies, each of saidassemblies including spaced vertical members and spaced horizontalmembers rigidly secured to said vertical members with each of saidhorizontal members constructed and positioned when said assemblies aremounted to receive and hold thereunder in deflected condition aplurality of spaced reinforcing members under tension to be embeddedwith said assemblies in concrete beams produced, a plurality ofchannel-shaped members, each of said deflecting assemblies having saidvertical members thereof removably secured to said channel-shapedmembers and projecting upwardly therefrom, each of said transverserecesses in said base receiving one of said channel-shaped memberstherein with said deflecting assemblies thereon projecting upwardlytherefrom and with said channel-shaped members being verticallyadjustably mounted on said bolt means of said anchoring means tovertically adjust said deflecting assemblies, mold means comprising amold member having sides, a top and a passageway therethrough and openin the end and bottom. portions and slidably mountable on said base tomove therealong in guided relation to said guide means, said baseforming the bottom of a mold in operation, said mold member having ahopper in the top to introduce concrete thereinto, constructed on itsinside to shape concrete therein in setting to a concrete member of adesired shape and to receive through said passageway said plurality ofreinforcing members when stretched between said end members and toreceive said deflecting assemblies, Winch means mountable on one of saidend members and having a cable therewith with said cable being attachedto said mold member to move same substantially the length of said baseduring the molding process, said apparatus adapted when said pluralityof reinforcing members are stretched and under pressure between said endmembers, deflected in contact with said deflecting assembly and passingthrough said mold member passageway to make a pre-stressed concretemember having said reinforcing members therein and having saiddeflecting assemblies therein by moving said mold member along said baseand introducing concrete thereinto through said hopper means.

2. The apparatus of claim 1 wherein said mold is of shape to produce anI-beam, said horizontal members of said deflecting assemblies are threespaced members the lower one of which is substantially longer than theother two and said horizontal members being of size and positioned toreceive and deflect four lower ones, two middle ones, and two upper onesof said reinforcing members, and said pre-stressed concrete membersproduceable by said apparatus are pre-stressed concrete I-beams withsaid reinforcing members in the lower half portion of said I-beams asproduced.

3. The apparatus of claim 1 wherein said mold means comprises aplurality of mold members side by side in spaced relation with each ofsaid mold members having sides, a top and a passageway therethrough andopen in the end portions, and each of said mold members having openhopper means in said top to introduce concrete thereinto.

4. Apparatus for making pre-stressed concrete structural members havingpre-tensioned reinforcing members therein under great tension,comprising, in combination, a base, a plurality of transverselyextending recesses in said base, an end member at each end of said base,guide means with said base and extending substantially the lengththereof, each of said end members having means constructed to anchor endportions of a plurality of said reinforcing members stretchedtherebetween under great tension and in vertical and horizontal spacedrelation, anchoring means in said transverse recesses in said base andhaving upwardly projecting bolt means, a plurality of permanentlyembedable deflecting assemblies, each of said assemblies includingspaced vertical members and spaced horizontal members rigidly secured tosaid vertical members with each of said horizontal members constructedand positioned when said assemblies are mounted to receive and holdthereunder in deflected condition a plurality of spaced reinforcingmembers under tension to be embedded with said assemblies in concretebeams produced, a plurality of channel-shaped members, said defleetingassemblies having said vertical members thereof removably securable tosaid channel-shaped members projecting upwardly therefrom, saidchannel-shaped members with said deflecting assemblies thereonprojecting upwardly therefrom mountable in said transverse recesses insaid base with said channel-shaped members vertically adjustably mountedon said bolt means of said anchoring means to vertically adjust saiddeflecting assemblies, mold means comprising a mold member having sides,a top and a passageway therethrough and open in the end and bottomportions and slidably mountable on said base to move therealong inguided relation to said guide means, said base forming the bottom of amold in operation, said mold member having means in the top to introduceconcrete thereinto, constructed on its inside to shape concrete thereinin setting to a concrete member of a desired shape and to receivethrough said passageway said plurality of reinforcing members whenstretched between said end members and to receive said deflectingassemblies, means attachable to said mold member to move samesubstantially the length of said base during the molding process, saidapparatus adapted when said plurality of reinforcing members arestretched and under pressure between said end members, deflecting incontact with said deflecting assembly and passing through said moldmember passageway to make a pre-stressed concrete member having saidreinforcing members therein and having said deflecting assembliestherein by moving said mold member along said base and introducingconcrete thereinto.

Equipment, February 1957, pages 138-140 and 149.

Hold Down Restrains, Concrete, September 1957, vol. 65, issue 9, page60.

Hold Down Anchors for Pretensioned, Prestress Concrete, SuperiorConcrete Accessories, Inc., Franklin Park, 111., Dec. 2, 1957.

